Yes, rainbow hair colors are all the rage right now (hello colombré!), but even a subtle change can make a huge difference. What do we mean? If you switch up the tone — think cool vs. warm — of your shade, it can really alter your look.

On the other end of the spectrum, there are cooler shades (platinum blonde, ash brown, black, and cherry) "that contain blues, violets, and greens and cool down your complexion," adds Dueñas. Don't believe the hype? Luckily, we have proof. In fact, we have examples for three very different hair colors.

Brown

On the left, Eva Longoria opted for a cool, dark brown. But as you can see, when she switched to a warmer hue, it really brought out the rosiness in her cheeks.

Red

We love Christina Hendricks in any shade of red. And judging from these pics, it's obvious she can pull them all off. The Mad Men star went for a dark copper on the left, which really makes her blue eyes pop. But on the right, she brightened her hair up with an orange-y hue that adds more color to her face.

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Blonde

Oh, Reese! Let us count the many ways we admire you. For now, we'll start with your hair, which has always been golden in our eyes. We especially love how you can move back and forth between cool and warm shades effortlessly — and still look flawless.

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So, who should add warmer tones to their hair? Michael recommends it to those who want to warm up their complexion. If you're feeling a little too pale for your liking, golden tones can add the brightness you desire. On the other hand, if you have a lot of redness in your skin and wish to neutralize it, shoot for a cooler tone.

If you don't want to choose between the two, you're in luck: having "neutral" hair doesn't mean you have to go with a flat, boring shade. In fact, you can blend different tones together to create the perfect shade of multifaceted ombre. Just ask your stylist for a cooler base with warm highlights framing your face, giving you the best of both worlds.